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<== Date ==> <== Thread ==>

Subject: Re: the length of channel name
From: "Ned D. Arnold" <nda@aps.anl.gov>
To: Bob Dalesio <ldalesio@lanl.gov>
Cc: Jeff Hill <johill@lanl.gov>, "'Marty Kraimer'" <mrk@aps.anl.gov>, "'Lifang Zheng'" <zhenglf@ssrc.ac.cn>, "'EPICS tech-talk'" <tech-talk@aps.anl.gov>
Date: Wed, 19 Mar 2003 11:39:48 -0600
Bob Dalesio wrote:
I will attmpt to make it clear
in 3.14 - you database allows you to have 60 character names
channel access allows you to search for much longer names
but......
you cannot change the fields within the database that may refer to names that are longer than 40 characters as the channel access type dbr_string is configured to be 40 characters. This means that you can define the database to link any of these 60 character named records together - but you cannot change them over channel access during operation.

Actually, it is the 40 character limit of dbr_string that dictates the conventional 28 character limit of a PV name ... IF you want to change a link field over channel access ... as follows:

1234567890123456789012345678901234567890
my_process_variable_name123.EGUF NPP NMS

This shows 27 characters max, but I think 28 still
works because of the way the NPP/NMS flags are
parsed.


Ned




References:
Re: the length of channel name Bob Dalesio

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